Poxvirus infected cells will be utilized to examine the synthesis and assembly of viral membranes and the mechanism by which the introduction of a viral genome into a host cell can result in alteration of the surface membrane of the infected cell. The mechanism of viral DNA replication and the possible role of viral specified membrane as the structural feature required for DNA replicase function will be examined. Finally, the mechanism by which host cell functions are inhibited by the introduction of a viral genome will be investigated.